Timken29526D#3Double Tapered Roller Bearing Cup – 4.4375 in Outer Diameter, 1.6875 in Cup Width, Class 3, e 0.46, K 1.27, Case-Hardened Steel

Product Description

What this part is

A Timken 29526D double tapered cup — a single one-piece outer race carrying two tapered raceways, one at each end, for two-row TDO service. Cup only. It seats in a housing bore and takes two single cones; the cones Timken pairs with it are the 29586 and the 29588. Outside diameter is 4.4375 in (112.713 mm) and outer ring width C is 1.6875 in (42.863 mm). Rings are case-hardened steel. Weight is 4.49 lb (2.036 kg).

Decoding the designation

In Timken’s tapered roller nomenclature the D suffix on a cup number marks a double cup: one ring, two raceways, two cone positions. The plain 29526 is the single cup of the same series. The trailing #3, also written *3 or -3, is Timken precision Class 3 — a tighter tolerance grade than the standard unsuffixed part, applied to bore, outside diameter, width and running accuracy.

Mounting and fitting data

The maximum housing fillet radius cleared by the cup corners is 0.03 in (0.8 mm). Housing backing shoulder diameter at the frontface (Da) is 4.15 in (105.40 mm). The e factor is 0.46 and the K factor is 1.27. Lubrication and life factors are Y1 1.47, Y2 2.19 and geometry factor Cg 0.111.

What these specs mean in practice

A TDO double cup sets the two rows back to back inside one ring, which gives a wide effective bearing spread. That spread is what makes the arrangement suited to positions where overturning moments are a significant part of the load, such as wheel ends, pinion supports and steering knuckles. The K factor of 1.27 places the raceway angle in the band that carries substantial thrust alongside heavy radial load, and because the two rows oppose each other the mounted pair locates axially in both directions. A TDO cup can be fixed in the housing or left free to float in the bore.

Precision class

Class 3 tightens the dimensional and running-accuracy tolerances over standard class. On a double cup this matters most for the relationship between the two raceways, since any error there is shared across both rows and shows up as runout at the shaft.

Quantity and configuration

One piece, one double cup. Two raceways in a single ring, open with no seal or shield, and no bore — the shaft fit is taken by the cones, which are separate parts ordered by their own numbers.

Interchange guidance

The cup is listed as 29526D, and the same ring appears written 29526-D, 29526D#3 and 29526D*3. Timken also catalogues a 29526DRB in the same envelope; the RB variant is a related size with its own ring detail rather than a straight substitution for the plain 29526D. The single cup 29526 shares the series but is a different part, carrying one raceway instead of two.